1. Field of the Invention
The present invention relates to a picture extracting apparatus and method. More particularly, the present invention relates to an improvement of a picture extracting apparatus and method in which picture signals of a picture area bounded by a reference frame are extracted from a film such as a microfilm or an ultramicrofilm where the reference frame is applied in the upper, lower, left and right borders.
2. Description of the Prior Art
FIG. 1 is a diagram showing a structure of a scanned picture area obtained by scanning of a reading sensor which constitutes a background for the present invention and to which the present invention is applied. Generally, for a picture recorded in a film such as a microfilm or an ultramicrofilm, a black frame exists for each frame of recording as shown in FIG. 1, that is, the black frame defines the upper, lower, left and right borders for each frame of recording. In a reading sensor for converting such tone in a film into an electrical signal, the scanning area of the reading sensor is made considerably larger than the picture area of one frame as shown in FIG. 1. This picture area is generally called a scanned picture area. This serves to make up for the tolerance of a film stop position of a positioning mechanism, or the irregularities in the recording conditions of the film or the optical conditions of a reading apparatus.
On the other hand, the desired picture area is an area of ABCD shown in FIG. 1. However, if picture signals of the scanning area are provided as they are, a picture having a black frame on the upper, lower, left and right borders is transmitted. In such case, the quality of a reproduced picture (a copy) is extremely deteriorated, resulting in decrease of the commercial value. At the same time, since a large amount of unnecessary picture signals must be transmitted, not a small loss is caused in the transmission efficiency or the transmission cost.